The present invention relates to a valve for a flexible reservoir for a substance in liquid or gel form, to the use of such a valve for making a device for packaging and dispensing substance, and to a method of packaging such a substance.
Valves already exist for delivering a substance contained in a flexible reservoir implemented in the form of a deformable bag that is enclosed in a rigid case in which there exists gas at a positive pressure.
The function of the compressed gas is to transmit a fraction of its energy (stored in the form of pressure) to the flexible reservoir and to the incompressible liquid substance so as to enable it to be ejected.
In general, such valves comprise firstly a cylindro-conical body defining at least part of a chamber for connection via a first end to a deformable bag forming a reservoir for substance and via a second end to a nozzle tube provided with an admission orifice and with a valve member, and secondly a collar for fixing in leak-proof manner to a rigid case suitable for containing said bag and a gas under pressure.
However, packaging devices fitted with a such valves present filling problems.
The substance is introduced into the bag directly through its mouth if the valve has not yet been mounted, or via the valve chamber if the valve is already in place.
The compressed gas is then injected into the volume lying between the inside wall of the case and the outer skin of the bag already full of substance via an independent orifice fitted with a specific valve.
The compartment for substance and the compartment for gas of the device are therefore filled in two successive operations, sometimes in the opposite order to that described above, but always via two distinct paths, thus requiring two different tools to be used.
An object of the present invention is to resolve these technical problems in satisfactory manner, in particular by simplifying the packaging method by using a single tool for filling purposes.
According invention, this objet is achieved by means of a valve of the type comprising firstly a cylindro-conical body which defines at least part of a chamber for connection via a first end to a deformable bag forming a reservoir for a substance and via a second end to a nozzle tube provided with an admission orifice and with a valve member, and secondly a collar for leak-proof fixing to a rigid case suitable for containing said bag and a gas under pressure; the valve being characterized in that the wall of said body is provided with at least one orifice for injecting the gas providing communication between the chamber and the case and suitable for being closed in leak-proof manner by an elastically-deformable wall bearing against said body around said orifice.
In a specific embodiment, said injection orifice is formed in the side wall of said body and the elastically-deformable wall is carried by a sleeve radially clamped around said body.
According to an advantageous characteristic, said nozzle tube is carried by a rod forming a valve member and suitable for sliding axially in said chamber to uncover the admission orifice of said tube while being urged by a spring towards a high closed position in which said admission orifice has no communication with the chamber.
In a specific variant, the rod is provided with at least one radial fin whose inside face serves as a bearing surface for the return spring.
According to an advantageous characteristic, said chamber is upwardly defined by at least one internal ring secured to said body and providing sealing, firstly when the valve is in the open position by clamping radially around a nozzle tube, and secondly while the valve is in the closed position, by bearing axially against said radial fin.
In a variant, said valve further comprises a coaxial outer ring fitted to the nozzle tube and acting in the valve closed position to wipe and close the admission orifice.
According to yet another characteristic, the collar is connected to the upper portion of said body by forming a shoulder.
In another variant, the admission orifice of the nozzle tube is situated in the side wall thereof.
In yet another variant, said sleeve is secured to an annular gasket mounted beneath said collar.
In a particular embodiment, said bag is connected to the chamber in strong and leak-proof manner by fastening to the wall of said body beneath the injection orifice.
In a variant, said chamber is extended inside the bag by a dip tube.
The invention also provides the use of the above-defined valve for making a device for packaging and dispensing a substance in liquid or gel form.
The invention also provides a method of packaging a substance in liquid or gel form in a reservoir formed by a deformable bag fitted with a valve whose body is provided with at least one injection orifice suitable for being closed by an elastically-deformable wall bearing against said body around said orifice, and designed to be enclosed under the pressure of a gas in a hermetic, rigid case, the method being characterized in that:
said valve is opened to put the bag into communication with the outside;
the bag is filled via the valve which is kept open until the level of substance reaches the bottom portion of the body; then
the gas under pressure is injected into the valve while it is kept in the open position, thereby elastically deforming the wall and uncovering the injection orifice so as to enable the case to be put under pressure; and
injection of the gas is stopped once the working pressure has been reached, thus causing said wall to return in leak-proof manner against the injection orifice, after which said valve is closed again, thus having the effect of pressing said wall in leak-proof manner against said orifice.
The valve of the invention thus performs two functions. In one direction it enables both the bag to be filled with substance and the case to be filled with drive gas, and in the opposite direction it enables said substance to be ejected without delivering any drive gas.
Packaging operations can thus be implemented in two immediately successive steps by means of a single tool fitted to the nozzle tube.
Consequently, this tool which bears against the nozzle tube can remain in place throughout the entire duration of packaging, thereby providing significant savings in time and in the means implemented.
To perform packaging in full, it suffices to use a set of control cocks and pressure gauges to feed said tool initially with the substance and then with compressed gas.
Furthermore, the valve of invention provides good sealing between the compartments for the substance and for the compressed gas, thus guaranteeing that distribution is of high quality and effectiveness regardless of whether the packaging device is used while it is upright, inclined, lying down, or upside-down.